Kazuo Katsumata

High incidence of sleep apnea syndrome in a male diabetic population

In order to study the possible relationship between sleep apnea syndrome (SAS) and diabetes mellitus, we first examined the prevalence of SAS among 12,787 general patients (6554 males and 6233 females) who visited Katsumata Hospital at Nagoya, Japan. Among them, thirty-five males and five females were diagnosed as having SAS. The male patients were statistically analysed by the corrected Mantel-Haenszel chi-square test taking the body type into account, and it was found that the prevalence of SAS was significantly high both in a diabetic population and in a hypertensive one. Among 40 SAS patients of both sexes, 34 were given a glucose tolerance test (GTT) with oral administration of 75 g glucose. Thirteen showed a diabetic pattern, 12 a borderline pattern and only 9 had a normal pattern. All 13 diabetic patients had non-insulin-dependent type diabetes (NIDDM). The present results showed that SAS has a close relationship not only to hypertension but also to NIDDM.

STUDIES ON THE DIETARY FACTORS IMPARING CARBOHYDRATE METABOLISM OF RATS

The ratio of nutrients which might impair carbohydrate metabolism was studied using male albino rats fed with various kind of diet. It was clarified that both the increased ratio of fat and the decreased ratio of carbohydrate + protein in the total calory consumed were the important dietary factor for the impairment of carbohydrate metabolism. The importance of this dietary ratio was discussed. Several authors have demonstrated that the amounts of circulating glucose in rats fed on a high-fat diet was increased, and these amounts were higher than those in animals fed on a diet rich in carbohydrates 1> 2>. A reduction in carbohydrate in the diet has been reported to cause the tissues to use up less carbohydrate and increase gluconeogenesis from protein 3>. Generally because high fat diet unevitably decreases the content of not only carbohydrate, but also protein in the diets, the role of protein and carbohydrate must be explored. The object of this study was to clarify the effect of carbohydrate and protein in the diet on the impaired carbohydrate metabolism of rats fed on a high fat diet, and also to investigate the ratio of nutrient imparing carbohydrate metabolism.

Effects of Palmitic Acid on the Binding of Insulin^-131I to the Rat Liver Mitochondria

Effects of palmitic acid, inhibitors, uncouplers, and reduced and oxidized glutathione on the binding of insulin-131! and 131! to the isolated fresh or aged mitochondria were studied. The binding of insulin-1311 to the fresh mitochondria was unexpectedly increased to a greater degree with the exogenous addition of palmitic acid, glutathione, acetaldehyde and 2, 4-dinitrophenol to the medium. The fact indicated that the intactness of mitochondria was not prerequisite for the binding of insulin-1311 to the isolated mitochondria. The binding of insulin-1311 was compared to the fresh mitochondria and the aged mitochondria. Insulin-131 [ bouud to the aged mitochondria in a lesser degree. It is suggested that the binding of insulin-1311 to the mitochondria might be related to the mitochondrial functional and conformational state. The binding of 1311 to the mitochondria was apparently differrnt from that of insulin-1311. And the binding of 1311 was not altered by these uncouplers except in the case of acetaldehyde and ethyl alcohol. This implies that the process of binding of insulin-131! is different from that of 1311. In the case of 1311, it may have some connections with its ion transport mechanism.